Pakistan is to put former military ruler General Pervez Musharraf on trial for treason for imposing emergency rule in 2007. Treason is punishable by death or life imprisonment.
Interior Minister Chaudhry Nisar Ali Khan said on Sunday the proceedings were being taken under under Article 6 of the Constitution after a ruling by the Supreme Court.
"It is happening for the first time in the history of Pakistan and the decision has been taken in the national interest," he said.
The Chief Justice would Monday will receive a letter from the government on Monday requesting the setting-up of a tribunal of three high court judges to start proceedings against Musharraf for treason.
The government will also announce a special prosecutor on Monday.
General Musharraf, 70, is already facing four cases dating back to his rule from 1999 - 2008, including one related to the assassination of former prime minister Benazir Bhutto in 2007.
Last week he asked a court to let him leave the country to visit his sick mother in Dubai. The court was expected to rule on the application on Monday.